JP7248222B2 - METHOD FOR MANUFACTURING HEAT CONDUCTIVE MEMBER, AND DISPENSER DEVICE - Google Patents

Description

The present invention relates to a method for manufacturing a thermally conductive member and to a dispenser device for use in, for example, a method for manufacturing a thermally conductive member.

2. Description of the Related Art In electronic devices such as computers, automobile parts, and mobile phones, radiators such as heat sinks are generally used to dissipate heat generated from heat generating bodies such as semiconductor elements and machine parts. It is known that a thermally conductive member such as a thermally conductive sheet is arranged between a heat generating body and a heat radiating body for the purpose of increasing the efficiency of heat transfer to the heat radiating body.
Thermally conductive sheets generally contain a polymeric matrix and a thermally conductive filler dispersed in the polymeric matrix. A thermally conductive sheet often has an anisotropic filler oriented in one direction in order to increase thermal conductivity in a specific direction.

A thermally conductive sheet in which an anisotropic filler is oriented in one direction is, for example, stretched, and a plurality of primary sheets are produced by extrusion molding or the like in which the anisotropic filler is oriented along the sheet surface direction. , is produced by curing or semi-curing a primary sheet, stacking a plurality of the primary sheets, and slicing the integrated body vertically. This manufacturing method is also called a flow orientation method. According to the flow orientation method, it is possible to obtain a thermally conductive sheet composed of a number of laminated unit layers with a very small thickness. Also, the anisotropic filler can be oriented in the thickness direction of the sheet (see, for example, Patent Document 1).

As the polymer matrix of the thermally conductive sheet, silicone resin is widely used from the viewpoint of thermal conductivity, heat resistance, and the like. However, when attempting to manufacture a thermally conductive sheet by the flow orientation method using a silicone resin as a polymer matrix, the adhesion between the primary sheets becomes weak, and the primary sheet and the primary sheet cannot be separated during the slicing process or the like. Problems such as peeling may occur between Therefore, for example, in Patent Document 2, when a silicone resin is used for the polymer matrix, the surface of the primary sheet is irradiated with vacuum ultraviolet rays (VUV) in order to increase the adhesiveness between the primary sheets, and then the primary sheet is It is disclosed to overlap.

JP 2013-254880 A WO2020/105601

However, as disclosed in Patent Literature 1, the method of forming a primary sheet by extrusion molding and then slicing the sheet has the problem that a large amount of offcuts is generated in each step, resulting in a large amount of material being wasted. Further, as disclosed in Patent Document 2, the use of VUV irradiation requires large-scale equipment, so it is desired to be able to manufacture with simple equipment.

Therefore, the present invention provides a method of manufacturing a thermally conductive member that can appropriately manufacture a thermally conductive member in which an anisotropic thermally conductive filler is oriented in one direction using simple equipment with little waste of materials. The object is to provide a method.

As a result of intensive studies, the present inventors have found that a thermally conductive composition having predetermined physical properties is discharged in sheets using a dispenser device having a wide discharge port and stacked to form a laminate. , found that the above problems can be solved, and completed the following invention. The gist of the present invention is the following [1] to [16].
[1] A push rod containing a liquid resin and an anisotropic thermally conductive filler and having a pressing surface with a diameter of 3 mm is pierced at a piercing speed of 10 mm/min. preparing a thermally conductive composition that is 60 gf;
a step of obtaining a laminate by discharging the thermally conductive composition in a sheet form using a dispenser device having a wide discharge port;
A method of manufacturing a thermally conductive member, comprising:
[2] the liquid resin is a curable liquid resin;
The method for producing a thermally conductive member according to [1] above, further comprising a step of curing the thermally conductive composition after obtaining the laminate.
[3] The method for producing a thermally conductive member according to [1] or [2] above, further comprising the step of cutting the laminate in a direction intersecting the plane of lamination.
[4] The method for producing a thermally conductive member according to any one of [1] to [3] above, wherein the liquid resin contains a volatile compound.
[5] The method for producing a thermally conductive composition according to [4] above, further comprising the step of volatilizing the volatile compound.
[6] The thermally conductive member according to any one of [1] to [5] above, further comprising a step of compressing the laminate in the lamination direction to compressively deform it to a thickness of 75 to 97%. manufacturing method.
[7] Any one of [1] to [6] above, wherein a plurality of sheet bodies are stacked on the laminate by stacking the thermally conductive composition discharged in sheet form while cutting. 10. A method for manufacturing the thermally conductive member according to claim 1.
[8] The thermally conductive member according to [7] above, wherein the thermally conductive composition discharged in the form of a sheet is cut by a cutter that is provided in the discharge port and moves along the longitudinal direction of the discharge port. manufacturing method.
[9] The method for producing a thermally conductive member according to any one of [1] to [6] above, wherein the thermally conductive composition discharged in sheet form is folded to obtain the laminate.
[10] The above [1] to [1] to [1] to [1] to [1] to [1] above, in which the thermally conductive composition is discharged between the heat radiator and the heat generator so as to be stacked in a plurality of sheets to form a laminate between the heat radiator and the heat generator. 9].
[11] The method for producing a thermally conductive member according to [10] above, wherein the thermally conductive composition is discharged in a sheet form in a direction connecting the radiator and the heat generator.
[12] The method for producing a thermally conductive member according to any one of [1] to [11] above, wherein each sheet member in the laminate has a thickness of 0.1 to 9.0 mm.
[13] The method for producing a thermally conductive member according to any one of [1] to [12] above, wherein the thermally conductive composition is discharged at room temperature.
[14] comprising a head and a supply path for supplying the fluid material to the head,
The head has a wide ejection port and a connection path connecting the supply path and the ejection port,
The dispenser device, wherein the connection path is connected to the ejection port with an inner diameter in one direction increasing from the supply path toward the ejection port.
[15] The dispenser device according to [14] above, further comprising a cutter arranged at the ejection port and moving along the longitudinal direction of the ejection port.
[16] The above-described [14] or [15], wherein at least one of the head and the member to which the fluid material is ejected is movable in a direction perpendicular to the longitudinal direction of the ejection port. dispenser device.

According to the present invention, it is possible to appropriately manufacture a thermally conductive member in which an anisotropic thermally conductive filler is oriented in one direction using simple equipment with little material waste.

It is a mimetic diagram showing a dispenser device concerning one embodiment. It is a front view which shows the head of a dispenser apparatus. FIG. 4 is a schematic diagram for explaining step 2 in the method for manufacturing the thermally conductive member according to the first embodiment; FIG. 5 is a schematic diagram for explaining step 5 in the method for manufacturing the thermally conductive member according to the first embodiment; FIG. 4 is a schematic cross-sectional view showing an example of a thermally conductive member; It is a schematic diagram for demonstrating the manufacturing method of the heat conductive member which concerns on 2nd Embodiment. It is a schematic diagram for demonstrating the manufacturing method of the thermally-conductive member which concerns on 3rd Embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. First, the dispenser device used in the method for manufacturing the thermally conductive member will be described below.

[Dispenser device]
As shown in FIG. 1 , the dispenser device 50 includes a head 51 and a supply channel 52 for supplying the fluid material to the head 51 . The head 51 has an ejection port 53 and a connection path 54 . The connection path 54 connects the discharge port 53 and the supply path 52 . A table 57 is provided below the head 51 , and the ejection port 53 faces the table 57 .
In this manufacturing method, the fluid material is a thermally conductive composition, has fluidity, and can maintain a certain shape (for example, a sheet shape) when discharged onto the table 57 or the like. I wish I had. Further, in the following description, the direction in which the fluid material is discharged is defined as MD (Machine Direction), and the lateral direction is defined as TD (Transverse Direction). MD is the direction orthogonal to TD. Also, the vertical direction perpendicular to both MD and TD will be described as ZD.

As shown in FIG. 2, the head 51 has a shape extending in the lateral direction (TD), and ejection ports 53 are provided on its lower surface 51A. The outlet 53 has a wide shape, ie an elongated shape with the transverse direction (TD) being the longitudinal direction, as shown in FIGS. Note that the ejection port 53 is generally rectangular.
The size of the ejection port 53 is not particularly limited, but the length L1 in TD is, for example, 2 to 100 cm, preferably 5 to 50 cm, and the length L2 in MD is, for example, 0.1 to 9.0 mm, preferably 1.5 cm. 0 to 5.0 mm. Also, the length ratio L1/L2 is, for example, 3-1000, preferably 5-500, more preferably 20-200.

The connection path 54 is connected to the ejection port 53 with an inner diameter in one direction (TD) increasing from the supply path 52 toward the ejection port 53 to a size corresponding to the length L1 of the ejection port. Further, the connection path 54 is connected to the ejection port 53 with the inner diameter in the direction perpendicular to the TD (MD) decreasing from the supply path 52 toward the ejection port 53 to a size corresponding to the length L2.

In dispenser device 50 , one end of supply channel 52 is connected to tank 56 . The tank 56 is provided with a pump (not shown), and the fluid material stored in the tank 56 can be supplied to the head 51 through the supply path 52 in a pressurized state by the pump. The supply channel 52 is formed by a pressure-resistant tube so as to supply pressurized fluid material.

The table 57 is movable along the MD (that is, the direction orthogonal to the longitudinal direction of the ejection port 53), and while the fluid material is being ejected from the ejection port 53, the table 57 moves in the MD, thereby The fluid material discharged from the outlet 53 flows into the MD and forms a sheet. The thickness of the ejected sheet-like fluid material is approximately the same as the length L2.
The table 57 is also movable in the ZD direction. For example, when the fluid material is discharged on top of the fluid material discharged in the form of a sheet, the table 57 is preferably moved downward.

The dispenser device 50 also includes a cutter 58 arranged at the discharge port 53 . In this embodiment, the cutter 58 is a wire cutter arranged below the lower surface 51A. Both ends of the wire cutter are attached to attachment portions 51X and 51Y provided on the head 51 . The mounting portions 51X and 51Y are movable along the TD (that is, the longitudinal direction of the discharge port 53) in the head 51, and by moving these mounting portions 51X and 51Y, the cutter 58 can also move in the lateral direction (TD). It is possible to move along By moving the cutter 58 to TD, the fluid material discharged from the discharge port 53 can be cut. Note that the cutter 58 may be omitted when the fluid material is not cut each time each layer is formed, as in a second embodiment described later.

Note that the dispenser device 50 may have a movable head 51 instead of the table 57 . Specifically, the head 51 may be movable in MD, and may be movable in ZD. By moving the head to the MD, the fluid material can be discharged in sheet form along the MD without moving the table 57 . Further, by moving the head to the ZD, it becomes possible to discharge more fluid material on top of the fluid material discharged in sheet form without moving the table 57 .
In the dispenser device 50, only one of the table 57 and the head 51 may be movable, but both may be movable.
Further, the member to which the fluid material is discharged (discharged member) does not have to be the table 57, and the table 57 may be omitted and a member other than the table 57 may be used. Alternatively, it may be a member arranged on the table 57 . These members to be ejected should be able to move along the ZD or MD like the table 57 .

Furthermore, the head 51 of the dispenser device 50 may be swingable about its upper end. When the head 51 swings around its upper end, for example, as shown in a third embodiment described later, when the fluid material is ejected between two members arranged above the ejected member, It is possible, for example, to bring the fluid material into contact with each of the two members and eject it.
In addition, although the dispenser device 50 has one tank 56 , when the liquid resin is of a two-liquid curing type, tanks for storing the first liquid and the second liquid are provided and supplied to the head 51 . It may be mixed just before and then supplied to the head 51 .

[First embodiment]
<Method for producing thermally conductive member>
Next, a method for manufacturing a thermally conductive member according to the first embodiment of the invention will be described in detail. A thermally conductive member according to the first embodiment is manufactured by a manufacturing method including steps 1 to 5 below. In the first embodiment, steps 1 to 5 should be executed in this order.
Step 1: Step of preparing a thermally conductive composition containing a curable liquid resin and a thermally conductive filler Step 2: Using a dispenser device, the thermally conductive composition obtained in Step 1 is formed into a sheet Step 3: Step of compressing the obtained laminate in the stacking direction Step 4: Step of curing the thermally conductive composition Step 5: Laminate crosses the laminate surface The process of cutting along the direction of

[Step 1]
In step 1, a thermally conductive composition is prepared that includes a curable liquid resin and a thermally conductive filler. The thermally conductive composition contains an anisotropic thermally conductive filler (hereinafter also simply referred to as "anisotropic filler") as a thermally conductive filler. The anisotropic filler is a thermally conductive filler having an anisotropic shape and an orientable filler. In this manufacturing method, since the anisotropic filler is oriented in the ejection direction in step 2, the thermal conductivity in one direction of the thermally conductive member can be increased. However, the thermally conductive composition contains a non-anisotropic thermally conductive filler (hereinafter also simply referred to as "non-anisotropic filler") in addition to the anisotropic filler as the thermally conductive filler. It is preferable to contain. Details of the thermally conductive filler will be described later.

The thermally conductive composition prepared in step 1 has a piercing load of 8 to 60 gf when the piercing speed is 10 mm/min. When the piercing load is less than 8 gf, when a plurality of sheet-shaped thermally conductive compositions discharged from the dispenser device are stacked, the thermally conductive composition spreads under its own weight and reaches a certain thickness or more. Problems such as the inability to obtain a laminated body having such an orientation and disordered orientation occur. Moreover, if it becomes larger than 60 gf, troubles, such as being unable to discharge a heat conductive composition from the dispenser apparatus 50, will arise. The piercing load is preferably 10 gf or more, more preferably 16 gf or more, from the viewpoint of further suppressing the spread due to its own weight. Moreover, from the viewpoint of improving the ejection property from the dispenser device 50, the piercing load is preferably 50 gf or less, more preferably 35 gf or less.
The piercing load at a piercing speed of 10 mm/min is the stress when the thermally conductive composition is pierced with a push rod having a pressing surface with a diameter of 3 mm at a piercing speed of 10 mm/min. The puncture load is measured at the temperature (discharge temperature) at which the thermally conductive composition is discharged from the discharge port.
The piercing load can be adjusted by appropriately selecting raw materials used for the thermally conductive composition. Specifically, the viscosity of the liquid resin, the type and amount of the anisotropic filler, the type and amount of the non-anisotropic filler described later, the presence or absence, type, and content of liquid components other than the liquid resin. etc. can be adjusted.

In the present invention, the thermally conductive composition needs to have a high viscosity so that it can be discharged from the dispenser in the form of a sheet and laminated to form a laminate. In general, as an indicator of the viscosity of the thermally conductive composition, the viscosity measured by a viscometer such as a Brookfield viscometer is generally used. In the case of a viscous composition, the rotor of a Brookfield viscometer may slip on the sample, making it difficult to accurately measure the viscosity with a viscometer.
On the other hand, the value of the piercing load is effective as an index representing the viscosity of a composition that contains a thermally conductive filler such as an anisotropic filler and has a high viscosity. Adopt a load.

The heat conductive composition preferably has a piercing load of 10 to 100 gf when the piercing speed is 100 mm/min. By setting the piercing load at a piercing speed of 100 mm/min within the above range, it is possible to further suppress spreading due to its own weight and to easily improve dischargeability from the dispenser device. From these points of view, the puncture load at a puncture speed of 100 mm/min is more preferably 13 gf or more, more preferably 25 gf or more, more preferably 75 gf or less, and even more preferably 45 gf or less.
The puncture load at a puncture speed of 100 mm/min can be measured in the same manner as the puncture load at a puncture speed of 10 mm/min, except for the puncture speed.
Further, the curable liquid resin preferably comprises a main agent and a curing agent for curing the main agent. In this case, in the step 1, a first liquid containing at least an anisotropic filler compounded in a curable liquid resin main component and a second liquid containing at least an anisotropic filler compounded in a curing agent of the curable liquid resin. and should be prepared. In addition to the anisotropic filler, the first liquid and the second liquid may contain other components such as a non-anisotropic filler and a liquid component, which will be described later. The first liquid and the second liquid may be mixed and stored in the tank 61 , or may be stored in separate tanks and mixed immediately before step 2 .

[Step 2]
The thermally conductive composition obtained in step 1 is preferably filled in the tank 56 of the dispenser device 50 (see FIG. 1). Then, by driving a pump (not shown), the thermally conductive composition in a pressurized state is supplied to the head 51 through the supply path 52, and heat is conducted as shown in FIG. The liquid composition R is discharged from the discharge port 53 to the outside. At this time, as shown in FIG. 3A, the sheet is placed on the table 57 by moving the table 57 in one direction of the MD (also referred to as the “forward direction”) as the thermally conductive composition R is discharged. The thermally conductive composition R is discharged in a shape.

After the thermally conductive composition R is discharged along the MD with a certain length, the cutter 58 is moved along the TD (perpendicular to the paper surface in FIG. 3), and as shown in FIG. A first sheet S1 is formed on the table 57 by cutting the thermally conductive composition R discharged from the discharge port 53 .

Next, as shown in FIG. 3(C), the table 57 is moved downward. Thereafter, as shown in FIG. 3(D), the thermally conductive composition R is discharged onto the sheet S1, and the table 57 is moved in the opposite direction along the MD (the direction opposite to the forward direction). Let
Then, after being discharged along the MD with a certain length, as shown in FIG. An eye sheet S2 is to be formed on the sheet S1.
After that, the table 57 is moved downward again, and the above operation is repeated to obtain a laminated body 22 in which a plurality of sheet members S1, S2, . See FIG. 4(A)). Although FIG. 4 shows a mode in which a large number of sheet bodies are stacked, the number of sheet bodies to be stacked (the number of layers) is not particularly limited as long as it is 2 or more, and may be, for example, 10 or more. Also, it may be about 1000 or less, or about 100 or less.

In step 2, the temperature (discharge temperature) at which the thermally conductive composition R is discharged from the discharge port 53 is preferably room temperature. By setting the discharge temperature to room temperature in step 2, the dispenser device 50 does not need to be provided with a heating device, and the device can be simplified.
In addition, room temperature here means that it is substantially the same as the environmental temperature in which a dispenser apparatus is installed. Therefore, the aspect in which the thermally conductive composition R is discharged from the dispenser device 50 without being heated by the heating device is also included in the aspect in which the discharge temperature is room temperature. A specific discharge temperature is, for example, about 0 to 40.degree. C., preferably about 10 to 30.degree.

In step 2, the thermally conductive composition R is discharged along the MD, so that the anisotropic filler blended in the thermally conductive composition R is oriented in the direction of discharge (MD). Accordingly, in each of the sheet members S1, S2, . . . Sn, the anisotropic filler is oriented along one direction (MD) along the surface direction of the sheet member. Then, as will be described later, the anisotropic filler is oriented along one direction along the surface direction even in the unit layer of the thermally conductive member, and thereby along the thickness direction of the thermally conductive member Orientation becomes possible.

To explain the orientation of the anisotropic filler more specifically, when the anisotropic filler is a fibrous filler as described later, one direction along the surface direction (MD, in the thermally conductive member described later) The ratio of the number of anisotropic fillers having an angle of less than 30° between the long axes of the fibrous fillers with respect to the thickness direction) exceeds 50% of the total amount of the anisotropic fillers. This ratio preferably exceeds 80%.
Further, when the anisotropic filler is a scaly filler, the scaly surface of the scaly filler forms with respect to one direction along the surface direction (MD, thickness direction in the heat conductive member described later). The ratio of the number of anisotropic fillers with an angle of less than 30° to the total amount of the anisotropic filler exceeds 50%, and the ratio preferably exceeds 80%. can do.

Regarding the anisotropic filler, from the viewpoint of increasing the thermal conductivity, the angle formed by the major axis or the scale surface with respect to one direction along the surface direction (MD, the thickness direction in the case of a thermally conductive member described later) The angle is preferably 0° or more and less than 10°, more preferably 0° or more and less than 5°. Note that these angles are the average values of the orientation angles of a fixed number (eg, 50 random anisotropic fillers) of the anisotropic fillers.
Furthermore, even when the anisotropic filler is neither fibrous nor scaly, the length of the anisotropic filler in one direction along the surface direction (that is, the thickness direction in the case of the MD, a thermally conductive member) It means that the ratio of the number of anisotropic fillers having an axis angle of less than 30° exceeds 50% with respect to the total amount of the anisotropic filler, and the ratio is preferably 80%. shall exceed.

Further, when the anisotropic filler is a scaly material, it is preferable that the normal direction of the scaly surface of the anisotropic filler faces a predetermined direction, specifically, the thickness direction of each sheet body. (ZD, stacking direction of a plurality of unit layers 13 to be described later) is preferable. Since the normal direction is oriented in the stacking direction in this way, the thermal conductivity in one direction (in the case of a thermally conductive member, the thickness direction) is improved. Moreover, the thermal conductivity along the surface direction of the sheet-like thermally conductive member and in the direction orthogonal to the stacking direction is also improved.
In addition, the normal direction of the scale surface faces the thickness direction of the sheet body (that is, the stacking direction) is the number of scale-like materials whose normal direction makes an angle of less than 30° with respect to the thickness direction (stacking direction). is in a state of exceeding 50%, preferably exceeding 80%.

In the laminate obtained in step 2, the thickness of each sheet S1, S2, . . . Sn is not particularly limited, but is preferably 0.1-9.0 mm. By setting the thickness of the sheet body to 0.1 mm or more, the thermally conductive composition R can be discharged without increasing the discharge pressure, and the thermally conductive composition containing a large amount of the thermally conductive filler can be discharged. Even the composition can be easily discharged. Moreover, the orientation of the anisotropic filler can be easily enhanced by setting the thickness to 9.0 mm or less. From these points of view, the thickness of each sheet member S1, S2, . . . Sn is more preferably 0.5 to 7 mm. In addition, the thickness of each sheet in the laminate may be compressed by the weight of the laminated thermally conductive composition itself with respect to the discharge thickness of the sheet (thickness of the unlaminated sheet). As a result, the thickness of each sheet body is, for example, 80% to 100%, preferably 90 to 100%, of the ejection thickness.

[Step 3]
In step 3, the laminate 22 obtained in step 2 is preferably compressed by applying pressure in the stacking direction. In step 3, by compressing the laminate 22 by pressurization, the plurality of sheet members S1, S2, . do. Since the plurality of sheet members are uncured, even when silicone resin is used as the liquid resin, the sheet members can be strongly adhered to each other by compression by pressure.
It is preferable that the laminate 22 is compressed and deformed to a thickness of 75 to 97% when the original thickness is 100%. By compressively deforming within the above range, it becomes easier to firmly bond the sheet members together without excessively deforming the laminate 22 . More preferably, the laminate 22 is compressed and deformed to a thickness of 85 to 95%.
It should be noted that the laminate 22 is plastically deformed by being compressed. Therefore, the thickness of the laminate 22 that has undergone compression deformation remains within the above range even if the laminate is released from the pressure. thickness will be maintained.
Compression of the laminate can be performed by applying pressure using, for example, rollers or a press. The pressure when applying pressure is not particularly limited, but as an example, when using a roller, the pressure is preferably 0.3 to 3 kgf/50 mm.

[Step 4]
Next, in step 4, the laminate compressed and deformed in step 3 is cured. The curing method may be appropriately set according to the type of liquid resin that can be cured. For example, if the curable liquid resin is photocurable, the laminate (thermally conductive composition) may be cured by irradiating the laminate with ultraviolet rays or the like. Moreover, if the curable liquid resin is thermosetting, the laminate (thermally conductive composition) may be cured by heating.
The curable liquid resin is preferably thermosetting. Therefore, curing of the thermally conductive composition in step 4 is preferably performed by heating. Specifically, for example, it may be carried out at a temperature of about 50 to 150.degree. Also, the heating time is, for example, about 10 minutes to 10 hours.

When a volatile compound is added to the thermally conductive composition as described later, the volatile compound may be volatilized at any timing. Specifically, it may be volatilized by heating during curing. More specifically, in the heating for curing, the thermally conductive composition is cured first, and the volatile compound can be volatilized by continuing the heating or by heating at a higher temperature.
However, it is preferable to volatilize by further performing a heating step after step 5 described later. This is because the sheet-like formation in step 5 allows the volatile compounds to be volatilized more efficiently than in the case of a laminate. Alternatively, a part of the compound may be volatilized by heating during curing, and the volatile compound may be further volatilized after step 5 described later.
When heating is performed after step 5, which will be described later, the temperature is not particularly limited, but the temperature is, for example, 70 to 170° C., preferably 100 to 160° C., and the heating time is, for example, about 30 minutes to 24 hours.

[Step 5]
Next, as shown in FIG. 4(B), the cured laminate 22 is cut along the stacking direction of the sheet bodies S1, S2, . 10 (thermally conductive sheet) is obtained. At this time, the laminate 22 is preferably cut in a direction orthogonal to the orientation direction of the anisotropic filler. As the blade 18, for example, a double-edged or single-edged blade such as a razor blade or a cutter knife, a round blade, a wire blade, a saw blade, or the like can be used. The laminate 22 is cut using a cutting tool 18, for example, by pressing, shearing, rotating, or sliding.
The cutting direction in step 5 is preferably a direction that matches the stacking direction, but may deviate from the direction matching the stacking direction as long as the direction intersects the stacking surface of the stack 22. .

According to the manufacturing method of the present embodiment described above, a thermally conductive member in which an anisotropic filler is oriented in one direction can be produced without using large-scale equipment and without generating scraps. can be manufactured. Therefore, it is possible to manufacture a thermally conductive member with good thermal conductivity with less waste of materials and with simple equipment.
In addition, according to the manufacturing method of the present embodiment, when obtaining the laminate 22, the thermally conductive composition R is cut for each layer, so that the thickness at the end of the laminate 22 tends to be uniform and Orientation becomes less likely to be disturbed, and generation of offcuts can be further suppressed.

[Heat conductive member]
An example of the thermally conductive member obtained by the above manufacturing method is shown in FIG. The thermally conductive member 10 is sheet-like and includes a plurality of unit layers 13 each containing a matrix resin 11 and a thermally conductive filler. A plurality of unit layers 13 are laminated along one direction x, and adjacent unit layers 13 are adhered to each other. In each unit layer 13, the matrix resin 11 serves as a matrix resin that holds the thermally conductive filler, and the matrix resin 11 is blended so that the thermally conductive filler is dispersed. The matrix resin 11 is obtained by curing the curable liquid resin described above, preferably a silicone resin. The direction x in which the unit layers 13 are laminated is perpendicular to the thickness direction z of the thermally conductive member.

The thermally conductive member 10 shown in FIG. 5 contains an anisotropic filler 14 and a non-anisotropic filler 15 as thermally conductive fillers. The anisotropic filler 14 is oriented in the thickness direction z of the sheet-like thermally conductive member 10 . That is, the anisotropic filler 14 is oriented along one direction along the surface direction of each unit layer 13 . Since the thermally conductive member 10 contains the anisotropic filler 14 oriented in the thickness direction z, the thermal conductivity in the thickness direction is improved. In addition, the thermal conductivity of the thermally conductive member 10 is further improved by further containing the non-anisotropic filler 15 .
However, the thermally conductive member 10 does not have to contain the non-anisotropic filler 15 .

In the thermally conductive member 10, the filling rate of the matrix resin 11 is preferably 15 to 60% by volume, more preferably 20 to 45% by volume, in terms of volume %, with respect to the entire thermally conductive member.
In addition, in the thermally conductive member 10, the filling rate of the anisotropic filler 14 is preferably 2 to 45% by volume, more preferably 8 to 35% by volume, based on the volume of the entire thermally conductive member. %. When the filling rate of the anisotropic filler 14 is within the above range, high thermal conductivity can be imparted to the thermally conductive member 10, and the dispenser device can be suitably manufactured.
In addition, when the non-anisotropic filler 15 is contained, the filling rate of the non-anisotropic filler 15 is preferably 10 to 75% by volume, and 30 to 60% by volume is more preferred.

The anisotropic filler 14 is exposed on both sides 10A and 10B of the thermally conductive member 10 in the thickness direction z. Also, the exposed anisotropic filler 14 may protrude from both surfaces 10A and 10B. Both surfaces 10A and 10B of the thermally conductive member 10 become non-adhesive surfaces by exposing the anisotropic filler 14 on both surfaces 10A and 10B. In addition, since both surfaces 10A and 10B of the thermally conductive member are cut with the above-described blade, the anisotropic filler 14 is exposed on both surfaces 10A and 10B. However, one or both of the surfaces 10A and 10B may be adhesive surfaces without exposing the anisotropic filler.

The thickness of the thermally conductive member 10 is appropriately changed according to the shape and application of the electronic device on which the thermally conductive member is mounted. The thickness of the heat-conducting member is not particularly limited, but is preferably in the range of 0.1 to 5 mm, for example.
The thickness of each unit layer 13 is not particularly limited, but is preferably 0.1 to 8.5 mm, more preferably 0.5 to 6 mm. The thickness of the unit layer 13 is the length of the unit layer 13 along the stacking direction z of the unit layer 13 .

Thermally conductive members are used inside electronic devices and the like. Specifically, the thermally conductive member is interposed between the heat generating body and the heat radiator, conducts the heat generated by the heat generating body, moves the heat to the heat radiator, and radiates the heat from the heat radiator. Here, the heating element includes various electronic parts such as a CPU, a power amplifier, and a power supply used inside the electronic equipment. Further, examples of heat radiators include heat sinks, heat pumps, metal housings of electronic devices, and the like. Both surfaces 10A and 10B of the thermally conductive member 10 are preferably in close contact with the heat generating element and the heat dissipating element, respectively, and are compressed when used.

[Thermal conductive composition]
Components used in the thermally conductive composition are described in detail below.
(liquid resin)
In this embodiment, the thermally conductive composition contains a curable liquid resin as described above. By using a curable liquid resin, it is possible to appropriately discharge the thermally conductive composition in a sheet form from the dispenser device, and to impart appropriate mechanical strength to the thermally conductive member by curing. In this specification, the term "liquid" refers to a liquid at 25°C and 1 atm. The curable liquid resin may be photocurable or thermosetting, but preferably thermosetting.

Specific examples of curable liquid resins include epoxy resins, polyurethane resins, silicone resins, acrylic resins, and polyisobutylene resins.
The curable liquid resin is not limited to the above, and may be acrylic rubber, nitrile rubber, isoprene rubber, urethane rubber, ethylene propylene rubber, styrene-butadiene rubber, butadiene rubber, fluororubber, butyl rubber, or the like. When these rubbers are used, uncrosslinked rubbers may be used, and the thermally conductive composition may be further blended with a crosslinking agent.

As the curable liquid resin, among the above, silicone resin is preferable. The silicone resin is not particularly limited as long as it is a thermosetting curable silicone resin, but it is preferable to use an addition reaction type one. In the case of an addition reaction type, the curable silicone resin preferably consists of a silicone compound (organopolysiloxane) as a main agent and a curing agent for curing the main agent.
The silicone compound used as the main agent is preferably an alkenyl group-containing organopolysiloxane. Specifically, vinyl-terminated polydimethylsiloxane, vinyl-terminated polyphenylmethylsiloxane, vinyl-terminated dimethylsiloxane-diphenylsiloxane copolymer, vinyl Examples include vinyl-terminated organopolysiloxanes such as dimethylsiloxane-phenylmethylsiloxane copolymers and vinyl-terminated dimethylsiloxane-diethylsiloxane copolymers.
The curing agent is not particularly limited as long as it can cure the above silicone compound as the main agent, but organohydrogenpolysiloxane, which is an organopolysiloxane having two or more hydrosilyl groups (SiH), is preferred.

The liquid resin is not particularly limited, but has a viscosity of, for example, about 30 to 2000 mPa·s, preferably about 100 to 500 mPa·s. By setting the viscosity within the above range, it becomes easier to adjust the penetration load within the above predetermined range. The viscosity here is the viscosity measured at a rotation speed of 10 rpm using a rotational viscometer (Brookfield viscometer DV-E, spindle SC4-14), and the measurement temperature is the temperature of the thermally conductive composition. It is the temperature at the time of discharge.
When the liquid resin consists of a main agent and a curing agent like the above silicone resin, the viscosity is the viscosity after the two are mixed.

(anisotropic filler)
The anisotropic filler is a thermally conductive filler having an anisotropic shape and an orientable filler. Anisotropic fillers include fibrous materials, scale-like materials, and the like. Anisotropic fillers generally have a high aspect ratio, with an aspect ratio greater than 2, and more preferably 5 or greater. By making the aspect ratio larger than 2, it becomes easier to orient the anisotropic filler in the ejection direction, and it becomes easier to increase the thermal conductivity of the thermally conductive member.

The upper limit of the aspect ratio is not particularly limited, but is practically 100.
The aspect ratio is the ratio of the length of the anisotropic filler in the long axis direction to the length of the short axis direction. means the longitudinal length/thickness of the scaly material.

The content of the anisotropic filler in the thermally conductive composition is preferably 10 to 500 parts by mass, more preferably 50 to 350 parts by mass, based on 100 parts by mass of the liquid resin. By setting the content of the anisotropic filler to 10 parts by mass or more, the thermal conductivity of the thermally conductive member can be easily increased. Moreover, by setting it within the above range, the value of the above-described piercing load of the thermally conductive composition tends to be appropriate.

When the anisotropic filler is a fibrous material, the average fiber length is preferably 10-500 μm, more preferably 20-350 μm. When the average fiber length is 10 μm or more, the anisotropic fillers in each thermally conductive member are brought into proper contact with each other to secure a heat transfer path and improve the thermal conductivity of the thermally conductive member.
On the other hand, when the average fiber length is 500 μm or less, the bulk of the anisotropic filler becomes low, so that it can be highly filled in the liquid resin.
In addition, said average fiber length can be calculated by observing an anisotropic filler with a microscope. More specifically, an electron microscope or an optical microscope is used to measure the fiber length of 50 arbitrary anisotropic fillers, and the average value (arithmetic mean value) can be taken as the average fiber length. .
For the anisotropic filler compounded in the thermally conductive member, for example, the average fiber length of the anisotropic filler separated by dissolving the matrix resin may be similarly measured. At this time, a large share should not be applied so as not to crush the fibers. Further, when it is difficult to separate the anisotropic filler from the thermally conductive member, the fiber length of the anisotropic filler may be measured using an X-ray CT device to calculate the average fiber length. good. In addition, in the present invention, an arbitrary one means a randomly selected one.

When the anisotropic filler is a scaly material, the average particle size is preferably 5-400 μm, more preferably 10-300 μm. Moreover, 20 to 200 μm is particularly preferable. By setting the average particle size to 5 μm or more, the anisotropic fillers in the thermally conductive member are likely to come into contact with each other, a heat transfer path is secured, and the thermal conductivity of the thermally conductive member is improved. On the other hand, when the average particle diameter is 400 μm or less, the volume of the anisotropic filler becomes low, and it becomes possible to highly fill the anisotropic filler in the liquid resin.
The average particle size of the scaly material can be calculated by observing the anisotropic filler with a microscope and taking the major axis as the diameter. More specifically, similarly to the average fiber length, an electron microscope, an optical microscope, and an X-ray CT device are used to measure the major diameters of 50 arbitrary anisotropic fillers, and the average value (arithmetic average value) can be taken as the average particle size. Similarly, the thickness of the anisotropic filler can be measured using an electron microscope, an optical microscope, and an X-ray CT apparatus.

The anisotropic filler should just use the well-known material which has thermal conductivity. Moreover, the anisotropic filler may have conductivity or may have insulation. If the anisotropic filler has insulating properties, the insulating properties of the thermally conductive member in the direction in which the anisotropic filler is oriented can be enhanced, so that it can be suitably used in electrical equipment. In the present invention, having conductivity means, for example, a case where the volume resistivity is 1×10 ⁹ Ω·cm or less. Moreover, having insulating properties means, for example, a case where the volume resistivity exceeds 1×10 ⁹ Ω·cm.

Specific examples of anisotropic fillers include carbon-based materials such as carbon fiber and scale-like carbon powder, metal materials and metal oxides such as metal fibers, boron nitride, metal nitrides, and metal carbides. , metal hydroxide, polyparaphenylene benzoxazole fiber, and the like. Among these, carbonaceous materials are preferred because of their low specific gravity and good dispersibility in liquid resins, and among them, graphitized carbon materials, which have high thermal conductivity, are more preferred. Boron nitride and polyparaphenylene benzoxazole fibers are preferred from the viewpoint of insulating properties, and boron nitride is more preferred. Boron nitride is preferably used as the scaly material, although it is not particularly limited. The scaly boron nitride may or may not be agglomerated, but it is preferred that part or all of it is not agglomerated.
An anisotropic filler may be used individually by 1 type, and may use 2 or more types together.

The anisotropic filler is not particularly limited, but generally has a thermal conductivity of 30 W/m·K or more, preferably 100 W/m·K, along the anisotropic direction (that is, the longitudinal direction). K or more. Although the upper limit of the thermal conductivity of the anisotropic filler is not particularly limited, it is, for example, 2000 W/m·K or less. The method for measuring thermal conductivity is the laser flash method.

An anisotropic filler may be used individually by 1 type, and may use 2 or more types together. For example, anisotropic fillers having at least two mutually different average particle sizes or average fiber lengths may be used as anisotropic fillers. When anisotropic fillers of different sizes are used, small anisotropic fillers enter between relatively large anisotropic fillers, allowing the anisotropic fillers to be densely packed in the liquid resin. It is considered that the heat transfer efficiency can be improved while the heat transfer efficiency can be improved.

Carbon fibers used as the anisotropic filler are preferably graphitized carbon fibers. Moreover, as the flake-like carbon powder, flake-like graphite powder is preferable. Among these, the anisotropic filler is more preferably graphitized carbon fiber.
Graphitized carbon fibers have graphite crystal planes aligned in the fiber axis direction, and have high thermal conductivity in the fiber axis direction. Therefore, by aligning the fiber axis directions in a predetermined direction, the thermal conductivity in a specific direction can be increased. Further, in the flake graphite powder, the crystal planes of graphite are continuous in the in-plane direction of the flake surface, and the in-plane direction has a high thermal conductivity. Therefore, by aligning the scale surfaces in a predetermined direction, it is possible to increase the thermal conductivity in a specific direction. Graphitized carbon fibers and flake graphite powder preferably have a high degree of graphitization.

As the graphitized carbon material such as the above-described graphitized carbon fiber, the following graphitized raw materials can be used. For example, condensed polycyclic hydrocarbon compounds such as naphthalene, PAN (polyacrylonitrile), condensed heterocyclic compounds such as pitch, etc. can be mentioned, but graphitized mesophase pitch, polyimide, and polybenzazole, which have a particularly high degree of graphitization, can be used. is preferred. For example, by using mesophase pitch, in the spinning process described later, the pitch is oriented in the fiber axis direction due to its anisotropy, and graphitized carbon fibers having excellent thermal conductivity in the fiber axis direction can be obtained.
The mode of use of the mesophase pitch in the graphitized carbon fiber is not particularly limited as long as it can be spun, and the mesophase pitch may be used alone or in combination with other raw materials. However, the use of mesophase pitch alone, that is, graphitized carbon fiber with a mesophase pitch content of 100% is most preferable from the viewpoint of high thermal conductivity, spinnability and quality stability.

Graphitized carbon fiber can be obtained by sequentially performing spinning, infusibilization and carbonization, pulverizing or cutting into a predetermined particle size and then graphitizing, or pulverizing or cutting after carbonization and graphitizing. can. When pulverizing or cutting before graphitization, condensation polymerization reaction and cyclization reaction tend to proceed during graphitization on the surface newly exposed by pulverization, so the degree of graphitization is increased and heat conduction is further improved. A graphitized carbon fiber with improved properties can be obtained. On the other hand, when the spun carbon fibers are graphitized and then pulverized, the graphitized carbon fibers are rigid and easy to pulverize, and a carbon fiber powder having a relatively narrow fiber length distribution can be obtained by pulverization in a short time.

The average fiber length of the graphitized carbon fibers is preferably 50-500 μm, more preferably 70-350 μm. In addition, the aspect ratio of the graphitized carbon fiber exceeds 2 as described above, preferably 5 or more. The thermal conductivity of the graphitized carbon fibers is not particularly limited, but the thermal conductivity in the fiber axis direction is preferably 400 W/m·K or more, more preferably 800 W/m·K or more.

(Non-anisotropic filler)
As noted above, the thermally conductive composition may further contain non-anisotropic fillers. A non-anisotropic filler is a material that, together with an anisotropic filler, imparts thermal conductivity to the thermally conductive member. In the present embodiment, since the non-anisotropic filler is contained, the filler intervenes in the gaps between the oriented anisotropic fillers, thereby obtaining a thermally conductive member with high thermal conductivity.
A non-anisotropic filler is a filler that does not substantially have anisotropy in shape. is a filler that is not oriented in a predetermined direction even in an environment where is oriented in a predetermined direction.

The non-anisotropic filler has an aspect ratio of 2 or less, more preferably 1.5 or less. By containing a non-anisotropic filler with a low aspect ratio in this way, a filler having thermal conductivity is appropriately interposed in the gaps between the anisotropic fillers, and a thermally conductive member with high thermal conductivity is obtained. Moreover, by setting the aspect ratio to 2 or less, it is possible to prevent the penetration load of the thermally conductive composition from increasing and to achieve high filling.

The non-anisotropic filler may have electrical conductivity, but preferably has insulating properties. It is preferred to have In this way, when both the anisotropic filler and the non-anisotropic filler are insulating, it becomes easier to further increase the insulation in the direction in which the anisotropic filler of the thermally conductive member is oriented.

Specific examples of non-anisotropic fillers include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides other than metals, nitrides, and carbides. Moreover, the shape of the non-anisotropic filler may be spherical or amorphous powder.
Examples of non-anisotropic fillers include metals such as aluminum, copper, and nickel; metal oxides such as aluminum oxide, magnesium oxide, and zinc oxide, such as alumina; and metal nitrides such as aluminum nitride. can do. Metal hydroxides include aluminum hydroxide. Furthermore, spherical graphite etc. are mentioned as a carbon material. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, and silicon carbide.
Among these, aluminum oxide and aluminum are preferable because they have high thermal conductivity and are easily available in spherical form. Aluminum hydroxide is preferable because it is easily available and can improve the flame retardancy of the thermally conductive member. .
Examples of non-anisotropic fillers having insulating properties include metal oxides, metal nitrides, metal hydroxides and metal carbides among those mentioned above, with aluminum oxide and aluminum hydroxide being particularly preferred.
The non-anisotropic fillers may be used singly or in combination of two or more.

The average particle size of the non-anisotropic filler is preferably 0.1-100 μm, more preferably 0.3-50 μm. Moreover, it is particularly preferable to be 0.5 to 15 μm. By setting the average particle size to 50 μm or less, problems such as disturbing the orientation of the anisotropic filler are less likely to occur. In addition, by setting the average particle size to 0.1 μm or more, the specific surface area of the non-anisotropic filler does not become unnecessarily large, and even if a large amount is blended, the penetration load does not increase easily, and the non-anisotropic filler It becomes easier to fill the material with high density.
The average particle diameter of the non-anisotropic filler can be measured by observing with an electron microscope or the like. More specifically, the particle size of 50 arbitrary non-anisotropic fillers is measured using an electron microscope, an optical microscope, and an X-ray CT device in the same manner as in the measurement of the anisotropic filler. An average value (arithmetic mean value) can be used as the average particle size.

The content of the non-anisotropic filler in the thermally conductive composition is preferably in the range of 50 to 1,500 parts by mass, more preferably in the range of 200 to 800 parts by mass, with respect to 100 parts by mass of the liquid resin. more preferred. When the amount is 50 parts by mass or more, the amount of the non-anisotropic filler present in the gaps between the anisotropic fillers becomes a certain amount or more, and the thermal conductivity is improved. On the other hand, by making it 1500 parts by mass or less, it is possible to obtain the effect of increasing the thermal conductivity according to the content, and the non-anisotropic filler inhibits the heat conduction by the anisotropic filler. Not at all. Furthermore, by setting it within the above range, the value of the above-described penetration load of the thermally conductive composition tends to be appropriate. Further, when the amount is in the range of 200 to 800 parts by mass, the thermal conductivity of the thermally conductive member is excellent and the piercing load is also suitable.

(liquid component)
The thermally conductive composition may contain a liquid component in addition to the liquid resin described above. By containing the liquid component, even if the content of the thermally conductive filler is increased, the penetration load can be easily adjusted within a predetermined range. Liquid components include volatile compounds and silicone oils, as described later. Either one or both of the volatile compound and the silicone oil may be used.
In the heat conductive composition, the liquid component other than the liquid resin is preferably 5 to 120 parts by mass, more preferably 10 to 80 parts by mass, still more preferably 15 to 50 parts by mass. By setting it within the above range, the penetration load can be adjusted within a predetermined range even if the content of the thermally conductive filler is increased.

(volatile compound)
In this specification, the volatile compound has a temperature T1 in the range of 70 to 300 ° C. at which the weight loss is 90% when the temperature is increased at 2 ° C./min in thermogravimetric analysis, and the boiling point (1 atmospheric pressure) is in the range of 60 to 200°C. Here, the temperature T1 at which the weight decreases by 90% is the temperature at which the weight of the sample before thermogravimetric analysis is 100%, and the weight decreases by 90% (i.e., the temperature at which the weight before measurement is 10%. ).

By containing a volatile compound, the thermally conductive composition can maintain a low penetration load even when the content of the thermally conductive filler is increased, and can improve the dischargeability when discharged from a dispenser device. On the other hand, volatilization during the manufacturing process of the thermally conductive member can increase the filling rate of the thermally conductive filler in the thermally conductive member. Therefore, by containing a volatile compound, the thermally conductive composition can increase the thermal conductivity of the thermally conductive member and also improve the ejection property.

Volatile compounds include, for example, volatile silane compounds and volatile solvents, among which volatile silane compounds are preferred.
Examples of the volatile silane compounds include alkoxysilane compounds. An alkoxysilane compound is a compound having a structure in which 1 to 3 of the 4 bonds of a silicon atom (Si) are bonded to alkoxy groups and the remaining bonds are bonded to organic substituents. Examples of alkoxy groups possessed by alkoxysilane compounds include methoxy, ethoxy, propoxy, butoxy, pentoxy, and hexatoxy groups. The alkoxysilane compound may be contained as a dimer.

Among the alkoxysilane compounds, an alkoxysilane compound having a methoxy group or an ethoxy group is preferable from the viewpoint of availability. The number of alkoxy groups possessed by the alkoxysilane compound is preferably 3 from the viewpoint of enhancing affinity with the thermally conductive filler as an inorganic substance. The alkoxysilane compound is more preferably at least one selected from trimethoxysilane compounds and triethoxysilane compounds.

Examples of functional groups included in the organic substituents of the alkoxysilane compound include acryloyl groups, alkyl groups, carboxyl groups, vinyl groups, methacrylic groups, aromatic groups, amino groups, isocyanate groups, isocyanurate groups, epoxy groups, hydroxyl groups, and mercapto groups. Here, when an addition reaction type curable silicone resin is used as the liquid resin and a platinum catalyst is used, it is preferable to select and use an alkoxysilane compound that hardly affects the curing reaction of the organopolysiloxane. Specifically, when an addition reaction type organopolysiloxane containing a platinum catalyst is used, the organic substituent of the alkoxysilane compound may not contain an amino group, an isocyanate group, an isocyanurate group, a hydroxyl group, or a mercapto group. preferable.

Since the alkoxysilane compound increases the dispersibility of the thermally conductive filler and facilitates high filling of the thermally conductive filler, an alkylalkoxysilane compound having an alkyl group bonded to a silicon atom, that is, an organic substituted It preferably contains an alkoxysilane compound having an alkyl group as a group. The number of carbon atoms in the alkyl group bonded to the silicon atom is preferably 4 or more. In addition, the number of carbon atoms in the alkyl group bonded to the silicon atom is preferably 16 or less from the viewpoint that the viscosity of the alkoxysilane compound itself is relatively low and the viscosity of the thermally conductive composition is kept low.

One type or two or more types can be used for the alkoxysilane compound. Specific examples of alkoxysilane compounds include alkyl group-containing alkoxysilane compounds, vinyl group-containing alkoxysilane compounds, acryloyl group-containing alkoxysilane compounds, methacrylic group-containing alkoxysilane compounds, aromatic group-containing alkoxysilane compounds, and amino group-containing alkoxysilane compounds. compounds, isocyanate group-containing alkoxysilane compounds, isocyanurate group-containing alkoxysilane compounds, epoxy group-containing alkoxysilane compounds, and mercapto group-containing alkoxysilane compounds. Among these, alkyl group-containing alkoxysilane compounds are preferred.

Examples of alkyl group-containing alkoxysilane compounds include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltri ethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane. Among alkyl group-containing alkoxysilane compounds, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltriethoxysilane. At least one selected from methoxysilane is preferred, at least one selected from n-octyltriethoxysilane and n-decyltrimethoxysilane is more preferred, and n-decyltrimethoxysilane is particularly preferred.

As the volatile solvent, a solvent having a boiling point (1 atm) of 60 to 200°C, preferably a boiling point of 100 to 130°C can be used. The volatile solvent preferably has a boiling point higher than the curing temperature of the organopolysiloxane by 10°C or more, more preferably 20°C or more.
As for the type of volatile solvent, a solvent that satisfies the above requirements can be appropriately selected, but it is preferable to use an aromatic compound such as toluene.
A volatile compound may be used individually by 1 type, and may use 2 or more types together.

The content of the volatile compound in the thermally conductive composition is preferably 5 to 100 parts by mass, more preferably 10 to 70 parts by mass, and still more preferably 12 to 45 parts by mass with respect to 100 parts by mass of the liquid resin. is.

(silicone oil)
The thermally conductive composition may contain silicone oil as described above. By containing a silicone oil and blending a volatile compound into the thermally conductive composition, even if the content of the thermally conductive filler is increased, the penetration load can be adjusted within a predetermined range. Therefore, it is possible to improve the ejection property of the thermally conductive composition while increasing the thermal conductivity of the thermally conductive member.

Examples of silicone oil include straight silicone oil and modified silicone oil. Straight silicone oils include dimethylsilicone oil (dimethylpolysiloxane), methylphenylsilicone oil (methylphenylpolysiloxane), and the like.
Modified silicone oils include, for example, polyether-modified silicone oils, aralkyl-modified silicone oils, fluoroalkyl-modified silicone oils, long-chain alkyl-modified silicone oils, higher fatty acid ester-modified silicone oils, higher fatty acid amide-modified silicone oils, and phenyl-modified silicone oils. oil.
Among silicone oils, straight silicone oils are preferred.
Silicone oil may be used individually by 1 type, and may use 2 or more types together.
The kinematic viscosity of the silicone oil is preferably 10 to 10,000 mm ² /s or less, more preferably 50 to 1,000 mm ² /s or less at 25° C., from the viewpoint of improving the ejection property of the thermally conductive composition. be.
The content of the silicone oil is preferably 1 to 70 parts by mass, more preferably 2 to 50 parts by mass, and still more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the liquid resin.

(Additional component)
Various additives may be added to the thermally conductive composition as long as they do not impair the function of the thermally conductive member. Examples of the additive include at least one or more selected from dispersants, coupling agents, adhesives, flame retardants, antioxidants, colorants, anti-settling agents and the like.
A curing catalyst or the like that accelerates curing of the curable liquid resin may also be added. Examples of curing catalysts include platinum-based catalysts when the liquid resin is a curable silicone resin. Moreover, when using an uncrosslinked rubber as a curable liquid resin, it may contain a cross-linking agent such as a sulfur compound or a peroxide.

[Second embodiment]
Next, a method for manufacturing a thermally conductive member according to the second embodiment will be described in detail.
In the first embodiment, a plurality of sheet bodies S1, S2, . On the other hand, in the present embodiment, the laminated body is formed by folding the thermally conductive composition (sheet body S) discharged in a sheet form without cutting with the cutter 58 each time each layer is formed. .
Only the points of difference between the second embodiment and the first embodiment will be described in detail below. Contents that will not be described below are the same as in the first embodiment.

In the present embodiment, as shown in FIG. 6A, as in the first embodiment, the table 57 is moved in one direction (forward direction) in the MD as the thermally conductive composition R is discharged. Then, the thermally conductive composition R is discharged onto the table 57 in the form of a sheet.
Next, in the present embodiment, after a certain length is discharged as described above, the thermally conductive composition R is not cut by a cutter, and the table 57 is left as it is as shown in FIG. 6(B). move downwards.
Thereafter, as shown in FIG. 6(C), the table 57 is turned inversely along the MD while the thermally conductive composition R is continuously discharged onto the thermally conductive composition R discharged onto the table 57. It is moved by a certain distance in a direction (a direction opposite to the forward direction described above). By repeating such operations, as shown in FIG. 6D, a plurality of sheets S made of the thermally conductive composition R are folded on the table 57 to obtain a laminate 22B. The number of layers of the laminate 22B is not particularly limited, and is as described in the first embodiment. The obtained laminate 22B is then preferably formed into a thermally conductive member by the same steps as in the first embodiment. The details of the resulting thermally conductive member are the same as in the first embodiment.

Also in the present embodiment, a thermally conductive member containing an anisotropic filler and having the anisotropic filler oriented in one direction without using large-scale equipment and without generating scraps. can be manufactured. Therefore, it is possible to manufacture a thermally conductive member with good thermal conductivity with less waste of materials and with simple equipment.
According to the manufacturing method of the present embodiment, when obtaining the laminate 22B, the thermally conductive composition R is not cut for each layer, and the folded portion 23B is provided at the end of the laminate 22B. The folded portion 23B tends to vary in thickness and may have a different thickness from portions other than the ends, or the orientation of the anisotropic filler may be disturbed. Therefore, in such a case, the folded portion 23B may be removed as appropriate. Although the cut-back portion 23B becomes scrap material that cannot be used as a heat conductive member, the amount of scrap material generated can be reduced compared to the case where the heat conductive member is manufactured by extrusion molding or the like.

[Modification of First and Second Embodiments]
The above first and second embodiments show one embodiment of the present invention, and the present invention is not limited to the above configurations, and various modifications are possible. Specifically, any one of the steps 3 to 5 may be omitted as appropriate.

For example, if Step 3 is omitted, the adhesiveness between unit layers in the thermally conductive member tends to be low, but it can be used in applications where high mechanical strength is not required. Further, when step 3 is omitted, step 4 hardens the laminate that is not compressed and deformed. Other configurations are similar to those of the first and second embodiments.
Also, if step 5 is omitted, the laminated body is used as it is as a thermally conductive member instead of a sheet-like thermally conductive member.

Also, for example, if Step 4 (that is, curing) is omitted, the thermally conductive member has low mechanical strength, so the thermally conductive member is preferably used in applications where high mechanical strength is not required. . If step 4 is omitted, it is not easy to cut the laminate, and for example, it becomes difficult to mass-produce thermally conductive members. 5 is also preferably omitted.
When step 4 is omitted, the liquid resin contained in the thermally conductive composition does not have to be a curable liquid resin, and may be a liquid resin that does not harden even when heated or irradiated with light. Specifically, for example, the non-crosslinked rubber described above may be used as the liquid resin, and the heat conductive composition may not contain a cross-linking agent.

In addition to steps 4 and 5, two or more of steps 3 to 5 may be omitted. For example, steps 3 and 4 may be omitted, or steps 3 and 5 may be omitted. Furthermore, all of steps 3 to 5 may be omitted. When Steps 4 and 5 are omitted, or when all of Steps 3 to 5 are omitted, the uncured liquid resin may be used as the matrix resin as it is, and the laminate may be used as it is as a thermally conductive member. .
Furthermore, in each of the above embodiments, the table 57 is moved to MD and ZD, but instead of moving the table 57, the head 51 may be moved to MD and ZD, or both the table 57 and the head 51 may be moved. You may let

[Third Embodiment]
Next, a third embodiment of the invention will be described. In the first and second embodiments, the thermally conductive composition was discharged onto the table 57 to form a laminate, but the thermally conductive composition may be discharged to a place other than the table 57, For example, it may be discharged onto a member to be actually used and used as a heat conductive member as it is. Specifically, it is preferable that the thermally conductive composition is discharged in a plurality of sheets between the heat radiator and the heat radiator to form a laminate between the heat radiator and the heat radiator.

Hereinafter, a method for manufacturing a thermally conductive member according to the third embodiment will be described in detail with reference to FIG. In the following description, only differences from the first and second embodiments will be described in detail, and the contents omitted from the description are the same as those in the first and second embodiments. Steps 1 and 2 may be performed sequentially as in the embodiment. That is, the thermally conductive composition prepared in step 1 is discharged from the head 51 of the dispenser device in step 2 to form the laminate 22C. In this embodiment, the laminate 22C may be formed as follows.
In the following description, the radiator 61 includes a base portion 61B and a side portion 61A connected to the base portion 61B. A mode in which the thermally conductive composition is discharged onto is described. Specific examples of the radiator 61 and the heat generator 62 are as described above.

First, as shown in FIG. 7, the radiator 61 and the heat generator 62 are placed on the table 57 . Then, between the side portion 61A of the radiator 61 and the heating element 62, the thermally conductive composition R is discharged onto the base portion 61B. At this time, similarly to the second embodiment, while moving the table 57 (that is, the heat radiator 61 and the heat generator 62) in the MD and downward directions, the sheet body S is folded to form a laminate 22C. Form. When discharging the thermally conductive composition R in forming the laminate 22C, the head 51 of the dispenser device is typically arranged between the radiator 61 and the heat generator 62, as shown in FIG. It will be.

Here, in the formation of the laminate 22C, the ejection direction (MD) of the thermally conductive composition R is the direction connecting the radiator 61 (side portion 61A) and the heat generator 62, and in the laminate 22C, the anisotropic The filling material is oriented in the direction connecting the radiator 61 (the side portion 61A) and the heating element 62 . Therefore, the heat generated by the heating element 62 can be efficiently transferred to the radiator 61 (side portion 61A) and radiated from the radiator 61 .

As described above, even in the present embodiment, an anisotropic filler is contained and the anisotropic filler is oriented in one direction without using large-scale equipment and without generating offcuts. can manufacture flexible parts. In addition, since large-scale equipment is not used, for example, it is possible to bring the dispenser device to the site where the electronic device is used and form the thermally conductive member between the heating element and the radiator at the site.

Furthermore, in the present embodiment, the laminate 22C made of the thermally conductive composition R is preferably formed so as to contact the side portion 61A of the radiator 61 and the heating element 62, respectively. The laminate 22</b>C is in contact with the side portion 61</b>A of the radiator 61 and the heat generator 62 , so that the heat generated by the heat generator 62 can be efficiently radiated from the side portion 61</b>A of the radiator 61 .
In order to bring the laminate 22C into contact with the side portion 61A of the radiator 61 and the heat generator 62, when forming both ends of the laminate 22C (that is, the folded portion 23C and its vicinity), as shown in FIG. In addition, the thermally conductive composition R may be ejected after the head 51 is oscillated about its upper end.

In this embodiment, the laminated body 22C formed between the side portion 61A and the heating element 62 as shown in FIG. 7 may be used as it is as a thermally conductive member. However, as in the first and second embodiments, one or both of step 3 and step 4 may be performed, but at least step 4 is preferably performed. The details of steps 3 and 4 are as described above.
Further, when performing step 4, as described in the first embodiment, the first liquid and the second liquid are prepared as the thermally conductive composition, and this is added immediately before step 2 Step 2 may be performed with mixing.

When step 3 is performed and the layered body 22C is compressed and deformed, the layered body 22C expands in the plane direction by a certain amount. Therefore, when performing step 3, it is not necessary to swing the head 51 when forming both ends of the laminate 22C.
By forming the layered body 22C without swinging the head 51 in step 2, even if both ends of the layered body 22C in the MD are not in contact with the side portions 61A of the radiator 61 and the heating element 62, the process can be performed. 3, the laminate 22C spreads in the MD, and the laminate 22C can be brought into contact with the side portion 61A of the radiator 61 and the heat generator 62. FIG.

Further, in the description of the third embodiment above, similarly to the second embodiment, the laminate 22C is not cut by the cutter 58 each time each layer is formed, and the laminate 22C is a sheet. A mode in which the body S is formed by being folded has been shown. However, as shown in the first embodiment, a plurality of sheet bodies S1, S2, . good too.

In this embodiment, the heat radiator 61 and the heat generator 62 are placed on the table 57 and moved in the MD and downward direction to obtain the laminate 22C. , the heating element 62 need not be arranged, and the table 57 may be omitted as long as the radiator 61 and the heating element 62 can be moved in the MD and downward direction. Also, as described in the first and second embodiments, the head 51 of the dispenser device may be moved in the MD and downward directions.

Further, in the present embodiment, the laminate 22C is formed by being laminated on a part of the radiator 61 (the base portion 61B), but the laminate 22C is formed on a part of the radiator 61. It is not necessary, and may be laminated on a separate member from the radiator 61 .

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

Raw materials used in Examples and Comparative Examples are as follows.
[Curable liquid resin]
Curable silicone resin: main agent consisting of alkenyl group-containing organopolysiloxane, curing agent consisting of hydrogen organopolysiloxane, viscosity of mixture of these at 25° C.: 300 mPa·s
[Liquid component]
Methylphenylpolysiloxane: kinematic viscosity at 25° C. 125 mm ² /s, refractive index 1.496
n-decyltrimethoxysilane: The temperature T1 at which the weight loss reaches 90% when the temperature is raised at 2°C/min in thermogravimetric analysis is 187°C.
[Anisotropic filler]
Boron nitride (1): scaly, aspect ratio 4-8, average particle size 40 μm
Boron nitride (2): scaly, aspect ratio 2-3, average particle size 10 μm
[Non-anisotropic filler]
Aluminum oxide (1): spherical, average particle size 0.5 μm
Aluminum oxide (2): spherical, average particle size 4 μm
Aluminum oxide (3): spherical, average particle size 71 μm
Aluminum hydroxide: amorphous, average particle size 1 μm

[Example 1]
(Step 1)
Alkenyl group-containing organopolysiloxane (main agent) and hydrogen organopolysiloxane (curing agent) as a curable silicone resin (100 parts by mass in total), 3 parts by mass of methylphenylpolysiloxane, and 12 parts by mass of n-decyltrimethoxysilane 168 parts by mass of boron nitride (1), 274 parts by mass of aluminum oxide (1), and 239 parts by mass of aluminum oxide (2) were mixed to obtain a thermally conductive composition. The penetration load of the resulting thermally conductive composition was as shown in Table 1.

(Step 2)
The obtained thermally conductive composition is filled in the tank of the dispenser device shown in FIG. From there, the thermally conductive composition was discharged at 25°C. At this time, the table was moved in the forward direction of the MD at a speed of 100 mm/min, and a sheet-like thermally conductive composition with a thickness of 3 mm was discharged by a length of 50 mm. After discharging 50 mm in length, the sheet-like thermally conductive composition was cut with a cutter to form a first sheet body on a table. After that, the table is moved downward, and then the table is moved in the opposite direction of the MD at a speed of 100 mm/min. A second sheet body was laid on top of the first sheet body. This operation was repeated until 20 sheets were stacked to obtain a laminate.

(Steps 3-5)
Next, in an environment of 25° C., a pressure of 1.5 kgf/50 mm was applied with a roller to obtain a compression-deformed laminate, and the laminate was cured by heating at 80° C. for 480 minutes. Then, it is sliced parallel to the lamination direction and perpendicular to the orientation direction of the anisotropic filler, and further heated at 150 ° C. for 300 minutes to volatilize n-decyltrimethoxysilane, and the thickness of each unit layer. A sheet-like heat conductive member having a thickness of 2 mm and a thickness of 2 mm was obtained.

[Examples 2 to 5, Comparative Examples 1 and 2]
The procedure was carried out in the same manner as in Example 1, except that the composition of the thermally conductive composition was changed as shown in Table 1.

[Puncture load]
The penetration load of the thermally conductive composition was measured by the following method.
The thermally conductive composition was defoamed, and 30 g of the defoamed thermally conductive composition was introduced into a cylindrical container with a diameter of 25 mm. Next, a piercing rod having a disk-shaped member with a diameter of 3 mm and a thickness of 1 mm at the tip (1 mm in diameter of the rod) was applied at a speed of 10 mm/min (piercing speed), and heat was introduced into the container from the tip side of the piercing rod. The load (gf) was measured when the tip of the piercing stick reached a depth of 12 mm from the liquid surface. The material of the stabbing rod was stainless steel. Measurements were made at 25°C.
The piercing load was also measured in the same manner when the piercing speed of the piercing rod was 100 mm/min.

Each example and comparative example were evaluated according to the following evaluation criteria.
(1) Dispensability of dispenser device In step 2, whether or not the thermally conductive composition could be discharged by the dispenser device, and if it could be discharged, the discharged thermally conductive composition formed a single layer. Whether or not it was maintained was visually confirmed and evaluated according to the following evaluation criteria.
A: It was possible to eject, and in the state of a single layer, there was no spread in the plane direction, and the ejected shape could be maintained.
B: Dispensable, in a single-layer state, the spread in the plane direction was slightly less than 10%, and the ejected shape was almost maintained.
C: It was possible to eject, but in the state of a single layer, the spread in the plane direction was large at 10% or more, and the ejected shape could not be maintained.
D: Could not be discharged.
(2) Lamination property In step 2, the shape retention property of the laminate obtained by laminating a plurality of sheet bodies was evaluated according to the following evaluation criteria.
A: A laminate was obtained that did not spread under its own weight and had a thickness as designed.
B: Although the laminate spread under its own weight, the spread was less than 25%, and a laminate having a thickness roughly as designed was obtained.
C: A laminate having a thickness as designed could not be obtained, with a large spread of 25% or more by its own weight.
(3) Compression test of laminate The compressibility (thickness change) when the laminate obtained in step 2 was pressed at a pressure of 1 kPa for 10 seconds is shown.
(4) Amount of offcuts generated The amount of offcuts generated in the process of obtaining the thermally conductive member was evaluated according to the following evaluation criteria.
A: Much of the extruded thermally conductive composition could be used to form the thermally conductive member.
C: Much of the extruded thermally conductive composition could not be used to form a thermally conductive member.
(5) Orientation of Anisotropic Filler In the obtained thermally conductive member, the orientation of the anisotropic filler was evaluated according to the following evaluation criteria.
A: The anisotropic filler was oriented in the thickness direction of the thermally conductive member.
B: The anisotropic filler was oriented in the thickness direction of the thermally conductive member, but the orientation was slightly disturbed.
C: The anisotropic filler was not oriented in the thickness direction of the thermally conductive member.

※なお、充填率は、ｎ－デシルトリメトキシシランを全量揮発したものとして、各成分の比重と質量部より算出した。

* The filling rate was calculated from the specific gravity and mass parts of each component, assuming that the entire amount of n-decyltrimethoxysilane was volatilized.

As shown in each example above, the anisotropic filler was oriented in one direction by discharging a thermally conductive composition having a predetermined penetration load in the form of a sheet using a dispenser device and laminating the composition. A thermally conductive member could be manufactured with good dischargeability, with little spread due to its own weight during discharge and lamination, and without disturbed orientation, and with a thickness as designed. In addition, the thermally conductive member can be manufactured without using large-scale manufacturing equipment, and almost no offcuts are generated in the manufacturing process. Therefore, it can be said that a thermally conductive member having good thermal conductivity could be manufactured with little waste of materials and with simple equipment.
On the other hand, in the comparative example, since the piercing load is low, when the thermally conductive composition is discharged in the form of a sheet using a dispenser device and laminated, the thermally conductive composition spreads due to its own weight during discharge and lamination. , the thermally conductive member could not be manufactured with the thickness as designed.

REFERENCE SIGNS LIST 10 thermally conductive member 11 matrix resin 13 unit layer 14 anisotropic filler 15 non-anisotropic filler 18 cutter 22, 22B, 22C laminate 23B, 23C folded portion 50 dispenser device 51 head 52 supply path 53 discharge port 54 Connection path 57 Table 58 Cutter 61 Radiator 62 Heating element R Thermal conductive composition S, S1, S2, ..., Sn Sheet body

Claims (13)

A push rod containing a liquid resin and an anisotropic thermally conductive filler and having a pressing surface with a diameter of 3 mm is pierced at a piercing speed of 10 mm/min. preparing a thermally conductive composition;
a step of obtaining a laminate by discharging the thermally conductive composition in a sheet form using a dispenser device having a wide discharge port;
A method of manufacturing a thermally conductive member, comprising: the liquid resin is a curable liquid resin;
2. The method of manufacturing a thermally conductive member according to claim 1, further comprising the step of curing said thermally conductive composition after obtaining said laminate. 3. The method of manufacturing a thermally conductive member according to claim 1, further comprising the step of cutting the laminate in a direction intersecting the plane of lamination. The method for producing a thermally conductive member according to any one of claims 1 to 3, wherein the liquid resin contains a volatile compound. 5. The method for producing a thermally conductive composition according to claim 4, further comprising volatilizing the volatile compound. The method for manufacturing a thermally conductive member according to any one of claims 1 to 5, further comprising a step of compressing the laminate in the lamination direction to compressively deform it to a thickness of 75 to 97%. The heat conduction according to any one of claims 1 to 6, wherein a plurality of sheet bodies are stacked on the laminate by stacking the thermally conductive composition discharged in the form of a sheet while cutting. A method for manufacturing a flexible member. 8. The method of manufacturing a thermally conductive member according to claim 7, wherein the thermally conductive composition discharged in the form of a sheet is cut by a cutter provided at the discharge port and moving along the longitudinal direction of the discharge port. The method for producing a thermally conductive member according to any one of claims 1 to 6, wherein the thermally conductive composition discharged in the form of a sheet is folded to obtain the laminate. 10. Any one of claims 1 to 9, wherein the thermally conductive composition is discharged between the heat radiator and the heat generator so as to form a plurality of sheets to form a laminate between the heat radiator and the heat generator. 10. A method for manufacturing the thermally conductive member according to claim 1. 11. The method of manufacturing a thermally conductive member according to claim 10, wherein the thermally conductive composition is discharged in a sheet form in a direction connecting the heat radiator and the heat generator. The method for producing a thermally conductive member according to any one of claims 1 to 11, wherein each sheet member in the laminate has a thickness of 0.1 to 9.0 mm. The method for producing a thermally conductive member according to any one of claims 1 to 12, wherein the thermally conductive composition is discharged at room temperature.

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